Field of the Invention
The present invention relates to an image forming apparatus, a method of controlling the same, and a storage medium.
Description of the Related Art
Conventionally, image processing apparatuses, such as printers and multifunction peripherals (MFPs), are known as apparatuses that form images on sheets (printing material). Recently, printers that operate in a so-called waiting print method in which, rather than immediately printing print data inputted from a PC (personal computer) or the like, start printing in accordance with an instruction of a user who directly operates the printer, have been more widespread.
In this waiting print method, there are cases in which print content is changed by a user immediately prior to the printing being performed. For example, a function by which it is possible to delete a particular page of a document that is stored on an image processing apparatus which is designated by a user, and the like have emerged.
Meanwhile, it is known that it is possible to register to a memory or a storage in an image processing apparatus, in advance, a page description language (PDL) resource (hereinafter referred to as a resource), such as a tile pattern or font data that is referenced at a time of PDL rendering processing as a PDL language specification. As such resources, groups of PDL commands (hereinafter referred to as commands) of a plurality of types are registered and managed by an ID (identification) or the like, in advance, and there are PDLs that can handle image profile data, overlays, macro control commands, or the like, used by executing a command group based on the ID.
In a typical PDL language specification, after an instruction to register a resource, as described above, is performed, it is possible to reference the resource from a plurality of different pages, and, in such a case, it is referred to as “resource inheritance level is job”, from the resource inheritance being inherited within the print job. Meanwhile, in a case in which a resource is valid only in a page for which the registration instruction is performed, and there is no inheritance between pages, it is referred to as “resource inheritance level is page”. A technique related to a method for managing resources that are inherited across a plurality of pages in this way is recited in, for example, Japanese Patent Laid-Open No. 2011-159219, and a method for deleting, from a memory, resources that are unnecessary after rendering processing is proposed thereby.
A preview function for displaying, on an operation screen, thumbnail images in units of pages in relation to a job for printing a saved PDL in such an authenticated print job, and a function for deleting a particular page prior to printing based on an instruction of a user that references a preview result are desirable. Note that, in processing for printing PDL data, unlike a copy or a facsimile, it is necessary to generate image data of a page by interpreting commands described in PDL, and therefore, the processing speed depends on the complexity of the PDL. Accordingly, it is desirable to delete unnecessary pages in advance.
However, in the case in which the language specification of the PDL is “resource inheritance level is job”, there is a problem in that the processing load for deleting a particular page is large. This is because referents of a resource of a page that is a deletion target are checked, and as long as it is not confirmed that the resource is not referenced in another page, the resource of the deletion target page cannot be deleted.